1. Field of the Invention
This invention relates generally to antimicrobial compounds and to topical compositions and wound dressings containing antimicrobial compounds. More particularly, the present invention provides dendritic polymer-metal containing composite materials and methods of using such materials for disinfecting and/or sterilizing wounds. Most particularly, the present invention provides composite compositions of matter in which discrete nanosized inorganic materials, for example, silver, cerium, zinc, etc., are distributed on or in a dendritic polymer, and in which the size and size-distribution of the nanosized inorganic materials are determined and controlled by the dendritic polymer.
2. Description of the Related Art
Silver is an effective antimicrobial agent with low toxicity which is particularly important in the topical antibacterial treatment of burn wounds where transient bacteremia is known to frequently occur in association with burn wound manipulation. Silver sulfonamides, particularly silver sulfadiazine (AgSD) has been a standard treatment for burns for at least the past two decades, either alone or in combination with other antibiotics, cerium compounds, zinc compounds and combinations thereof It has been suggested that the basic function of the almost insoluble AgSD may be to slow the release of silver into the superficial wound environment. Silver chloride was assumed to form at the burn wound and absorption of silver was believed to be negligible. In accordance with this assumption, it has been found that serum and tissue silver levels with 10% silver nitrate used in bums produced no difference from that of 1% silver sulfadiazine cream.
However, sulfonamide-resistant organisms have been reported as a frequent consequence of the clinical use of sulfadiazine silver. It was also shown that the sulfadiazine component is not necessary for in vitro sensitivity and that the use of sulfadiazine silver can, in every case, lead to the selection of organisms that are resistant not only to sulfonamides but to antibiotics of clinical consequence. Despite major advances in burn wound management and other supportive care regimens, infection remains the leading cause of morbidity and mortality in the thermally injured patient, and a search for different treatments and new ideas is continuing. Application of silver-binding membranes has recently been suggested to further reduce the likelihood of silver toxicity to retard the movement of silver ions and minimize silver absorption at a healing wound. See Greenfield, E., McManus, A. T., Nurs. Clin. North Am., 1997, 32(2), 297.